As the technology develops continuously, how to implement vibration damping has become a problem that receives more and more attention, especially on transportation facilities that have severe vibrations, such as automobiles. When the automobile runs, the vibrations mainly come from two sources, one of which is vibrations transferred from the road pavement via the tires and vibration absorbers to the main body of the automobile, and the other of which is vibrations transferred from the engine via the engine mount to the main body of the automobile. Therefore, as an important component that has effect on the vibrations, the engine mount has direct influence on the driving comfort of the automobile.
A good engine mount must have low dynamic stiffness against high-frequency vibrations and a high damping coefficient against low-frequency vibrations. In the prior art, engine mounts are mainly in two categories, that is full rubber mounts and hydraulic mounts. Due to the fact that the dynamic stiffness and loss coefficient of full rubber mounts are inherent characteristics of rubber material and will increase as the vibration frequency increases, ordinary rubber mounts can't meet the requirements of technical development. In order to improve the performance of rubber mount to meet the requirement for low dynamic stiffness against high-frequency vibrations and high damping coefficient against low-frequency vibrations, Volkswagen (Germany) pioneered to employ a mount with a liquid sealing structure in 1979, i.e., the so-called hydraulic mount. In addition, as consumers' demand for driving comfort of automobiles is higher and higher, hydraulic mounts are widely applied in all kinds of automobiles increasingly.
A hydraulic mount for engine was disclosed in CN2849321Y. As shown in FIG. 1, the hydraulic mount comprises a fixing base 11, an elastic body 12 arranged in the fixing base 11, and a support 13 that is integral with the elastic body 12 and is connected to the inner wall of the fixing base 11, an upper chamber 21 and a lower chamber 22 which are separated by a partition 20 are formed below the elastic body 12, wherein, the upper chamber 21 and the lower chamber 22 are communicated with each other through an orifice formed in the partition 20, a damping fluid is sealed in the upper chamber 21 and the lower chamber 22. In addition, in order to ensure the damping performance of the hydraulic mount, the chambers shall have no air as far as possible.
The disadvantages of such existing hydraulic mounts include: first, due to the complex structure, it is difficult to discharge air from the chambers thoroughly during the assembling process, and thereby the damping performance of the hydraulic mount will be affected directly. Second, in order to ensure that there is no air in the chambers as far as possible, usually the product is assembled and the damping liquid is filled in a liquid environment, as the result, the working environment is poor, the working space is moist, and the workers' hands have to be immersed in liquid for long, which has a strong impact on the workers' physical health. Moreover, since the product is assembled in a liquid environment, the workers are unable to see the assembling process directly; therefore, products with poor quality are often manufactured in the assembling process, and it is difficult to control the filling amount of the damping liquid.